


How to Raise Your Brother

by knowmeknot



Category: Undertale (Video Game)
Genre: Fluff, Gen, Kid Sans, Post-Undertale Pacifist Route, Protective Papyrus
Language: English
Status: In-Progress
Published: 2017-04-06
Updated: 2017-09-16
Packaged: 2018-10-15 07:19:27
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 8,078
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10552314
Author URL: https://archiveofourown.org/users/knowmeknot/pseuds/knowmeknot
Summary: A science experiment mishap regresses Sans to the age of 5 along with his memories. Papyrus takes it upon himself to become the caretaker for his younger, older brother just as Sans had done all those years ago. Tooth-rotting fluff ensues.Will accept prompts.





	1. Keep Him Away from the Labs

**Author's Note:**

> This fic is mainly for when I get writer's block. It'll be more like a series of one-shots and drabbles with a central theme. As a result, I will be accepting prompts/requests. This was inspired after reading [Agraulis_vanillae babybones drabble.](http://archiveofourown.org/works/9566813/chapters/22616456)

Papyrus was hanging out with Undyne when he received the call from Alphys. She had stuttered more than her usual and had sounded, not exactly fearful, but definitely nervous. It reminded him of when he’d first met the ex-Royal Scientist. Alphys had given up the title of Royal Scientist since reaching the Surface. She still worked in the field of science, as a biomedical engineer for a pharmaceutical company interested in integrating monster magic with modern medicine. The job has definitely boosted her confidence but her most recent phone call worried Papyrus. After all, Sans was also working there. He hoped that nothing happened to his older brother.

He and Undyne arrived at the lab where Alphys worked in record time. The lizard scientist greeted them with a strange mix of excitement and worry. 

“So what’s up, Alphys, something explode? Cuz that would be COOL!” Undyne roared as she gave the shorter monster a forceful pat on the back. Alphys gulped audibly, and her beady eyes trailed to Papyrus.

“S-something h-happened I-I’m s-s-sorry, Papyrus!” 

Papyrus felt a tightness in his chest, dread flooding his entire soul. 

“WHAT HAPPENED TO SANS? IS HE OK?” 

“I d-d-don’t exactly know. I-it was an a-accident. P-perhaps it’s b-b-best if I just show you.”

Papyrus and Undyne followed Alphys as she swiped her key card, and a windowless steel door slid open. A cylindrical machine took half the space in the room. Shelves overflowing with textbooks, binders and folders lined along the perimeter of the wall. 

“I l-l-left him in my o-office so he c-c-couldn’t accidentally-hurt himself.”

Papyrus almost wanted to scream at Alphys to just tell him what had happened, but that would have been rude. He took several deep breaths to calm himself. The three monsters reached the back door of the spacious lab. Alphys unlocked the door and swung it open to reveal a bundle of familiar clothes—a blue hoodie, white t-shirt along with black track shorts— lying in the far right corner, away from the desk. Papyrus was sure he heard rattling coming from it. 

“Uh, so… um, Sans was helping me test the new formula and, um, h-he turned… y-y-younger,” Alphys trailed off to barely a whisper at that last word.

With his soul pounding against his ribs, Papyrus slowly approached the quivering pile of clothes.

“SANS?” he called out hesitantly.

The shifting suddenly stopped and a small round skull peaked out of the blue hoodie. A pair of large, bright white eye lights peered up him. They were much larger than their usual size and were tinged with fear. Papyrus noticed faint blue stains underneath the sockets, most likely from dried tears. The sight caused his soul to constrict painfully. He was just about to reach out a gloved hand when Undyne abruptly sprang out behind him.

“Whoa! This is Sans?! You’re so tiny! Even more so than usual!”

Undyne bent down to pick up the diminutive bundle of bones. Sans shot up in an attempt to run away, only to trip over his baggy clothes. 

_Clack!_

And fell flat on his face.

All three larger monsters froze, with Undyne staring like a deer caught in headlights. There were two sharp intakes of breaths, and then pained sobs ripped out of the fallen skeleton.

“UNDYNE, YOU SCARED HIM!” Papyrus scolded his best friend. 

He then turned towards his brother and placed a gentle hand on his back, rubbing soothing circles. He resisted the urge to scoop Sans up into his arms, not wanting to further scare him. 

Alphys frantically ran out the office to get the first aid kit, dragging Undyne along with her. 

“IT’S OK, SANS, UNDYNE DIDN’T MEAN IT!” Papyrus reassured, continually stroking his brother’s back. It seemed to have calmed him down as the sobs subsided to sniffles and quiet whimpers. Papyrus took this opportunity to introduce himself. “HELLO, I AM PAPYRUS!” 

Sans finally turned around to look at him. Beads of blue tears clung to the corners of Sans’s sockets. A round area of bone just above his nose hole had the telltale signs of a developing bruise. But what really got to Papyrus was the ever-so-slight tooth gap between Sans’s two front teeth. If he wasn’t fretting over Sans’s injury, Papyrus would’ve been fawning. His brother was such a cute babybones!

Before Papyrus could get another word in, Alphys and Undyne came back with the first aid kit. Sans shrank back at the sight of the fish monster, which she noticed. Guilt marred her features. 

“NOT TO WORRY, SANS, THE GREAT PAPYRUS IS HERE TO PROTECT YOU!” He gave a comforting pat on his brother’s shoulder.

Alphys hesitantly drew closer and held up the first aid box. “H-h-hey Sans. D-do you m-mind if I take a look at w-where you fell?”

Despite her soft tone, Sans shook his head and grabbed at Papyrus’s left leg. His brother didn’t even reach his hips. 

“papy,” a high-pitched voice uttered, catching all three monsters off-guard. Papyrus almost didn’t recognize it. He directed his attention to his brother, who stared back at him with bright eye lights. “papy is my brother so he should do it.”

A rush of joy burst into the tall skeleton and before he could stop himself, Papyrus scooped up his much younger brother and wrapped his arms around Sans in a tight hug.

“WHY, OF COURSE YOUR COOL AND AWESOME BROTHER WILL DO IT!”

Papyrus sat Sans on top of the office desk and motioned at Alphys to hand over the kit. After opening it, he only found medications and items used to treat cuts. There wasn’t even monster food in there. Nevertheless, he rubbed some analgesic ointment on the area where Sans had hit his face and placed a small band-aid on it. Sans giggled as Papyrus’s phalanges brushed against the spot. 

Wowie! His brother was too cute! And apparently ticklish. He would have to explore this new discovery at a later time.

“S-s-so, Sans, d-do you, uh, remember what h-happened?” Alphys asked timidly.

Sans leveled the scientist with a confused look, gave a haphazard shrug and turned to Papyrus for an answer.

Did his brother not remember? Yet recognized Papyrus as his brother? How peculiar!

“HOW OLD ARE YOU, SANS?”

The corners of Sans’s permanent smile dipped and his eye lights trembled ever so slightly. Papyrus could tell the question upset him. 

“OF COURSE I KNOW YOUR AGE, BROTHER. THIS IS SIMPLY A TEST TO SEE IF YOU KNOW! IT’S TO KEEP YOU SHARP AS A KNIFE!”

Thankfully Sans believed him and held up five fingers. Alphys gasped.

“Dang!” Undyne exclaimed. 

Sans scrambled behind Papyrus at the loud proclamation. Undyne gave an apologetic glance as she stepped closer to Alphys and away from the two skeletons. 

“O-o-oh no!” Alphys clambered around on her desk, throwing papers this way and that until she came across a crumpled sheet of notebook paper. “Here it is! Just give me a bit of time Papyrus, and I’ll find a way to reverse this.”

“WHAT EXACTLY HAPPENED?”

“YEAH? Why’s Sans a kid?”

“W-w-well, um, you know how w-we were working together find a w-way to s-slow aging?” Undyne nodded, and Papyrus followed suit, even though he had no idea at all. “We f-found a formula that in t-theory should’ve w-worked… b-but, uh, I guess it wasn’t the c-correct one. S-s-sorry, i-it’s all m-my f-f-fault! I-I-I’m such a s-screw up!” Alphys stared at her feet despondently as tears pricked her eyes. 

A hand settled on her shoulder. “Hey, Alphys, you’re not a screw up! We’ll figure out this together!”

Papyrus nodded in agreement, “YES, AND I AM NOT ANGRY AT YOU AT WHAT HAPPENED, ALPHYS! BESIDES, THIS WILL GIVE ME THE OPPORTUNITY TO BE A BIG BROTHER FOR SANS! I’VE ALWAYS WANTED TO BE A BIG BROTHER!! AREN’T YOU EXCITED, SANS? SANS?!”

The watery smile on Alphys’s face quickly slipped away as the three older monster saw the empty spot on the desk where Sans had been sitting. Before mass panic broke out, however, she suddenly felt a light pat at her side. 

“alphy is scientist?” The lizard monster turned to see Sans standing behind her in his oversized clothes, barely clinging to his body, patting a sleeve-covered hand against her lab coat. “that’s pretty… _sans_ ational.”

Silence fell in the room. 

Alphys giggled first, followed up by guffaws from Undyne. Papyrus gave his usual infuriated groan at his brother’s horrible jokes but a wide smile soon replaced it. He picked up his brother and hugged him tightly, pleased that his brother’s pun had lightened the mood. Before long, laughter filled the room.


	2. It is Okay to Ask for Help

**Summary for the Chapter:**

> Prompt by gargryphmaster from tumblr: So we know that papy is the sweetest monster ever, but he can be... a bit delusional at times. but raising a child requires a lot of attention to detail and knowledge, which I'm going to assume that papyrus does not have. so, without sans being there to give him praise and such maybe he can wake up a little bit and realise that he is not perfect. maybe he can make some mistakes while raising lil sans and grow to over come his flaws?

Papyrus excitedly bounced throughout his house, carrying the five-year-old Sans everywhere he went. He was giving his brother a tour of their home since Sans didn’t remember any of it. He recited elaborate stories during the whole thing, warmth flooding his soul every time Sans would clap his tiny hands together or beam brightly at him. He had never raised a child before, but of course the Great Papyrus would be the best at taking care of his brother. Alphys and Undyne had offered their assistance if he needed it. Papyrus was so confident in his abilities that he cordially declined the offer. Sans had raised him by himself, after all, and look how great he turned out. 

Surely, it couldn’t be that hard, could it?

After the tour, Papyrus assumed that Sans would be hungry, and decided to make his signature spaghetti. Since his brother had always praised him for how much his cooking’s been improving, he couldn’t wait for little Sans to try out his new spaghetti recipe. Instead of putting sprinkles in it, he put pieces of dinosaur egg oatmeal. No doubt Sans would love it!

Unfortunately for Papyrus, Sans took one forkful of it and his face scrunched together in a grimace. He didn’t eat another bite, sending disappointment crashing through Papyrus. 

Where were his brother’s usual praises?

“HOW WAS IT, SANS?”

His small brother shrugged and pushed the plate of pasta noodles away. 

“it’s _pastable_. but not hungry.”

“OH, I SEE. THAT’S FINE! YOU CAN SAVE IT FOR—” Papyrus narrowed his sockets at Sans, whose teeth curled into a mischievous grin. “WAS THAT A PUN?!”

Sans giggled in response, and then gave a wide yawn, drowsily rubbing his sockets with a fist. Papyrus thought it was the most adorable thing. He picked up his brother into his arms and carried him upstairs. The smaller skeleton snuggled against his chest, filling Papyrus’s soul with absolute joy. Sans was already asleep by the time they reached his room, so Papyrus tucked him into bed. He pulled out a thick blanket to cover his brother. It was quite chilly this evening, and it wouldn’t be good for Sans to get sick. He then bounded back downstairs to plan all the puzzles he would teach Sans.

His brother woke up the next morning grumpy and lethargic. There was a faint dusting of blue across his cheekbones, and his normally bright eye lights were dim. Too excited to care, Papyrus simply pulled Sans right out of bed. The blanket had somehow ended up on the floor sometime during the night. 

He was going to teach his brother how to solve the word unscramble. Unfortunately, Sans barely paid attention and, instead, drew stars in the corners of the page. Even after Papyrus had completed the whole puzzle, the tiny skeleton stared listlessly at the numerous other books on their shelf. Papyrus ignored the pang that pulsed within his soul from his brother’s lack of attention and response.

He then decided that Sans was simply hungry and tried feeding the leftover spaghetti to him. His brother would turn his head away every time the noodles neared his teeth. His attempts at feeding Sans oatmeal and steamed vegetables were also refused.

“WHAT DO YOU WANT TO EAT THEN SANS!” 

Papyrus wasn’t getting angry; he was simply a bit annoyed. How could his brother refuse his amazing cooking?

“ketchup,” came the simple response.

“YOU ARE NOT EATING THAT, SANS! IT IS UNHEALTHY! EAT YOUR OATMEAL WITH VEGETABLES!”

“nada chance.”

“YES YOU WILL!”

“no.” 

“YES!” 

“no!”

“FINE! IF YOU DON’T LIKE YOUR COOL BROTHER’S SPAGHETTI, OATMEAL OR VEGETABLES, I’LL SIMPLY HAVE TO MAKE SOMETHING UNTIL YOU LIKE IT!” 

Papyrus set his brother down in front of the TV and turned it onto some cartoon about a cat chasing a mouse.

“paaapy,” Sans whined, not enticed by the cartoon.

“WAIT HERE, BROTHER, WHILE I WHIP UP SOMETHING GREAT!”

Papyrus ruminated on all the foods he’s ever learned to make from Undyne. There’s spaghetti, passionately smashed vegetables, and half-made chicken alfredo. A thorough survey of the fridge revealed no chicken, only some onions, peas and tomatoes. He threw all the ingredients in a large pot and cranked up the heat. 

Maybe some soup would fit Sans’s fussy tastes. Was _he_ ever this picky as a babybones? He also needed to go grocery shopping. He could even bring Sans along with him.

While waiting for his concoction to simmer on the stove, Papyrus stepped back into the living room to check on Sans. A stab of fear shot through him when he found his brother lying face-down on the couch.

“SANS?” 

Papyrus took three large strides to reach the couch and hastily pulled Sans into his arms. A weak groan escaped from the diminutive monster. Beads of sweat lined his forehead, and the blue hue in his cheeks had darkened considerably since the morning. Hazy, flickering eye lights peered back at him through barely opened sockets.

“SANS?! ARE YOU SICK?” 

The now-younger sibling shook his head weakly and tried to give Papyrus a bright smile. It only came off tired and forced.

“‘m fine, papy.”

A bare, skeletal hand settled lightly on Sans’s forehead, and Papyrus pulled back as if burned. It wouldn’t be too far off given the heat radiating from the petite skeleton. 

“WORRY NOT, BROTHER, I WILL TAKE GREAT CARE OF YOU!” Papyrus tried his best to suppress the panic quickly consuming his soul. “I KNOW! YOU NEED FLUIDS! AND NUTRIENTS!” 

He darted into the kitchen to get his brother a glass of water, then paused briefly. He opened a cabinet, immediately spotting the half-full bottle of ketchup. Wanting to do anything to make his brother better, Papyrus grabbed it. 

“LOOK, SANS! I’VE FINALLY BROUGHT YOU KETCHUP!”

No response came back at him. Papyrus knelt beside his brother and held the glass of water to his teeth. Most of it slipped onto the couch. The ketchup was also a failure, most of it dribbling back out of his brother’s mouth as if he were bleeding. Sans remained unresponsive with his chest rising and falling at a rapid pace.

Disheartened and worried beyond belief, Papyrus tried to think of a time when he was sick. Most of the memory was muddled, but he remembered hearing his brother’s soothing voice, drinking some sort of warm broth, and Sans giving him a bath.

A bath! Maybe that would help his brother feel better.

The smell of smoke suddenly wafted into his nose hole and a shrill beeping came from the ceiling in the kitchen.

“OH NO! THE FOOD!”

Papyrus sprinted into the kitchen to find smoking billowing from the stove. He promptly shut it off and opened a window. After experiencing several fires while cooking, Sans had recommended he crack a window open to air out the smoke. Just as he did, the sound of retching reached his nonexistent ears.

He dashed back into the living room to see Sans bent over the side of the couch, a puddle of blue and yellow magic residue on the carpet. Shivers wracked his entire frame.

“SANS!”

His brother winced slightly and mumbled back in a shaky tone, “s-sorry... i make a mess.”

Papyrus quickly placed a comforting hand on Sans’s skull. “IT’S OKAY, BROTHER, I’M NOT ANGRY!”

For the first time since he’d found Sans like this, Papyrus was at a loss of what to do. If only his older brother were here to help. Was he… not as great as he alway thought he was? Did Sans go through this much difficulty when raising him?

A series of dry heaves shook him out of his thoughts. Seeing his current brother’s pitiful state, Papyrus grabbed his phone and dialed Undyne’s number.

“Yo, Pap! How’s—”

“SANS IS REALLY SICK, AND NOTHING I DO SEEMS TO BE HELPING!” The words poured out of his mouth without hesitation. 

It didn’t matter that he was admitting his weakness; he only wanted his brother to get better.

“I hear ya, Pap. I’m busy at the moment but I promise to get you help.”

The next fifteen minutes was one of the most fear-inducing moments of his life thus far. Sans had fallen unconscious, still shivering uncontrollably. Papyrus fed his brother some more water; thankfully, it stayed down this time. 

As soon as he heard the doorbell, he was at the door within two seconds. To his surprise, Toriel greeted him. She carried two large bags on her shoulders.

“Undyne and Alphys told me what happened. How is he, dear?” the former queen asked.

Papyrus led Toriel to the couch that Sans laid in, a blue, wool blanket covering his tiny body. 

“I’M NOT SURE. PLEASE DO WHATEVER YOU CAN TO SAVE HIM!” 

A furry paw rested tenderly on Sans’s forehead. Green healing magic shimmered brightly underneath the paw before dissipating. The effect was instantaneous; his brother’s breathing eased to a much calmer rhythm, and the flush lessened in color. Toriel faced him and gave a warm smile.

“I’ve lowered the fever but the rest is up to him. May I borrow your kitchen?”

Papyrus nodded, feeling equal parts relieved and anxious, and led the goat monster into the kitchen. She wrinkled her nose at the burnt smell, and blinked twice at the contents of the pot. Without saying a word, she moved it aside to pull out a steel pot of her own, one that was almost a foot tall. 

“Soup is good to give to help him stay hydrated. I can make enough to last several days.” She set aside an assortment of vegetables, flat noodles and some chicken. 

“THANK YOU, MISS TORIEL. I TRIED DOING WHAT I COULD BUT… I seemed to have only made things worse.” 

Papyrus hung his head, wringing his hands together. A paw settled on his right shoulder.

“You shouldn’t blame yourself, Papyrus, and I’m sure Sans doesn’t either. Taking care of a child is not a simple task, but myself and others are always here to help you,” the boss monster offered kindly. 

It was true. Even though there were still things that the Great Papyrus didn’t know, he would give it his all to learn. He’d even get a parenting book next time.

In much higher spirits, Papyrus marched back into the living room to keep watch of Sans while Toriel cooked. He decided to carry his brother back into his bedroom so that Sans could rest in his cool racecar bed. He laid Sans down and drew up the red comforter.

“FROM NOW ON, BROTHER, I'LL LEARN FROM MY MISTAKES AND BECOME AN EVEN COOLER BROTHER-PARENT! NYEH HEH HEH!” 

Sans finally stirred, staring at him with pearly eye lights filled with the familiar admiration that Papyrus had seen so many times in his brother.

“you’re already the coolest, papy.”

Pride and joy filled his soul.

“WELL OF COURSE I AM, SANS!”

_Only because I was raised by someone as great and cool as you._

**Notes for the Chapter:**

> Remember, prompts are welcomed and if it works, I'll write it. Future ideas:  
> \- Sans's magic begins acting up (since he's young again) and he starts teleporting everywhere, intentionally and not intentionally.  
> \- Flowerpot!Flowey meets him and they don't get along.  
> \- Something with Papyrus acting as a protective bro  
> \- Since this is also taking place in the surface, Sans meeting other humans?  
> \- The reverse of this chapter (e.g. Pap gets sick and Sans tries to take care of him.)
> 
> Any other ones you guys come up with, feel free to add them to the list.


	3. Beware of Bunnies

**Summary for the Chapter:**

> Sans watches a “children's” movie that ends up scaring him. Who better to protect the small skeleton child than the Great Papyrus?

**Notes for the Chapter:**

> Thanks to **gargryphmaster** for [this fanart.](https://gargryphmaster.tumblr.com/post/159588909127/fannnn-arrrttttt-for-the-amazing-knowmeknot101) It's awesome and adorable. :3

Papyrus had believed it to be a wonderful idea at the time. He worked part-time as a security guard at a mall (it was the closest job he’d found to being a Royal Guard) and had gotten called in to work a shift. Undyne and Alphys were left to babysit his recently-turned-younger brother. Papyrus came home to find his brother, his best friend and her girlfriend all sitting on the couch watching a cartoon movie about rabbits. Both Undyne and Alphys were enraptured by the movie, catching Papyrus by surprise since the movie wasn’t the typical anime that Alphys always gushed about. In fact, said scientist had her hands pressed tensely into her face with her eyes glued to the screen. 

A startled gasp ripped Papyrus’s attention away from the scene of two large rabbits fighting viciously against each other. Blown out white eye lights stared at the scene in open horror. The two rabbits, one heavily scarred, tore at each other in the movie, and red liquid that humans called blood spattered everywhere. The visceral sight sent a shudder through Papyrus. If he found this unsettling, there's no way that his brother didn't feel the same way, and it was his duty both as Sans’s cool brother and a mall security officer to protect his brother! Papyrus marched in front of the TV with hands on his hips.

“THIS MOVIE IS MUCH TOO VIOLENT FOR SANS!” He scolded at the two female monsters.

“What are you talking about, Pap! This movie’s a classic for children according to some of my students' parents!” Undyne worked as a gym teacher for the local school that Toriel opened. The fish monster pumped up her fist. “Did ya see how those two rabbits fought? It was awesome!”

“no, papy! i wanna finish the movie,” his brother argued. 

“If it makes you feel better, Papyrus, the movie’s almost over,” Alphys added.

Papyrus peeked behind him and saw that the fight scene was over, and the surviving rabbits were regrouping.

“C’mon, Pap! I’m sure this movie will toughen up your babybones of a brother.” Undyne turned to the tiny skeleton and gave a grin full of teeth. “Isn’t that right, Sans?”

“yeah, ‘m not scared, papy! please!” Sans stared at Papyrus with large, bright, pleading eye lights. The puppy-eye expression was a critical hit to Papyrus’s soul. He stepped away from the TV.

“ALRIGHT, BROTHER, BUT IN RETURN, YOU HAVE TO EAT YOUR VEGETABLES!”

Sans’s scrunched his bone brows in disgust. “yuck! vegetables taste bad.”

“PROMISE ME, SANS, OR NO MOVIE!”

Sans huffed and grumbled, “fine. i promise.”

Papyrus still was second guessing himself with this decision as he cooked. Late that night, Papyrus was awoken by his brother’s horrified screams. Thankfully, and sadly, he was quite familiar in dealing with Sans’s nightmares. He arrived in Sans’s room within three seconds and was greeted with a quivering lump on the bed.

“SANS?” 

“no... get away…from papy,” the smaller skeleton whimpered.

Papyrus had no idea what his brother could be dreaming, but he assumed it was the same one his brother always had. The ones of a him getting dusted by a little human. Sans had finally admitted it to him not long before Sans had de-aged. It tore Papyrus apart that his brother had dealt with these horrible night terrors for so long, and they still plagued his brother even with the memory loss.

Papyrus tenderly placed a bare hand on Sans’s diminutive shoulder and drew languid circles against it. His brother’s trembling eventually lessened, and a soft sigh escape from behind his clenched teeth. Sans’s sockets opened to reveal dim, hazy eye lights. 

“papy safe from… them...” Sans’s trailed off and shuddered violently.

Papyrus scooped his brother into his lanky arms to give a tight hug. “NOT TO WORRY BROTHER! THE GREAT PAPYRUS WILL PROTECT YOU!” He rubbed soothing strokes down Sans’s spine. “DO YOU WANT TO TALK ABOUT IT?”

He felt his brother shake his head vehemently against his pajama shirt. A minute later and a soft voice mumbled, “t’was a stupid dream. i’m not scared. i’ll be brave and cool like you.”

“OF COURSE, BROTHER!” 

Warmth flooded his soul from Sans’s words. Papyrus didn't press further, wanting to give Sans the opportunity to tell him when he was ready.

The nightmares continued for two more nights, but his stubborn sibling still refuse to talk to Papyrus about it no matter how the taller skeleton tried to coax it out. The distressing dreams also left Sans grumpy and sad during the day. Wanting to cheer his brother up, Papyrus decided to bring Sans with him to the mall on Sunday. His co-workers had mentioned that the Easter Bunny would be there. He was sure his brother would be most excited to meet them, even though this would be the first time his brother would be in the presence of humans since becoming a babybones again. 

Sans pressed his sockets against the glass window of Papyrus red convertible as he drove to the mall. Large eye lights trailed along the different types of cars and scenery they passed, and Sans would excitedly point out any new discovery that fascinated him. 

To Papyrus’s surprise, when they arrived at the mall, his brother didn't shy away from the humans. Instead, he stared at them with opened fascination.

“papy, are those all humans?” He asked with sockets the size of saucers. 

Several teenage and young adult humans even stopped to fawn over his brother, who was finally wearing clothes his size after a kind donation from Frisk. Sans responded to their comments with his usual smile and a joke or two, always causing Papyrus to shout in exaggerated anger and making the humans laugh. Behind his irritated facade, joy and pride grew within Papyrus’s soul at the sight of his and his brother’s popularity. He knew taking his brother out had been an excellent idea.

The good feelings abruptly ended when Papyrus brought his brother to see the Easter Bunny. A mingling of human and monster children stood on line. As soon as Sans saw the big white furry rabbit with its wide, piercing stare and toothy grin, he froze as if trapped by blue magic. His white pupils shrank into pinpricks. The Easter Bunny, seemingly sensing Sans’s distress, approached the skeleton brothers in a slow pace, arms held upward in reassurance. 

Except that only frightened the small skeleton more. Sans shakedly backed away and ran off in the opposite direction of the Easter Bunny, stumbling as he did so.

“SANS!” Papyrus called out frantically. He briefly turned back to the Easter Bunny. “I APOLOGIZE, IT SEEMS THAT MY BROTHER DOES NOT LIKE YOU VERY MUCH.” And dashed after his brother.

Papyrus found Sans in a clothing store, hiding in a rack of clearance sale clothes. His size 1 kid sneakers that lit up whenever he walked gave his hiding spot away. As Papyrus made his way over, a small-sized galaxy pullover hoodie caught his sockets. Various shades of blue and purple adorned the article of cloth with countless white specks for stars. Papyrus pulled the jacket from its rack and held it close him.

“SANS? PLEASE COME OUT, I HAVE PREVENTED THE EASTER BUNNY FROM FOLLOWING US!!” he called out.

Only a wet sniffle came as a response. 

“PLEASE, BROTHER? I FOUND YOU THIS AWESOME JACKET! I’LL GET IT FOR YOU IF YOU COME OUT!”

Still, his brother remained in the sea of cheap clothes. 

A minute later, his brother’s muffled response came out, “i’m not brave like you, papy.”

The statement caught the tall skeleton completely by surprise. 

“WHAT DO YOU MEAN?”

He received no response. The events of the past three days rushed through Papyrus’s head. 

Could it be that Sans was afraid of rabbits now because of that movie? That was when his brother’s nightmares had started. It also explained his fear of the Easter Bunny.

Papyrus crept right next to where he saw Sans’s distinctive sneakers and sat down. 

“EVERYONE HAS FEARS, SANS, EVEN SOMEONE AS GREAT AS I. IT DOESN’T MEAN YOU AREN’T BRAVE,” he reassured. 

“b-but… mine’s dumb. none of the other kids are ‘fraid of rabbits.” 

Papyrus’s soul twisted at his brother’s despondent tone. He thought back to any strange fears he’s ever had and one came to him easily. One that Sans himself had helped him overcome by playing his ill-timed incidental music every time the canine stole his bones, making Papyrus angry laugh instead of shake in fear. 

“YOU KNOW, BROTHER, I WAS ONCE AFRAID OF SOMETHING WHITE, FURRY AND SMALL AS WELL. THE ANNOYING DOG THAT ALWAYS PLAGUED ME! I USED TO RUN FROM IT ALL THE TIME! BUT DO YOU KNOW HOW I OVERCAME IT?”

There was a rustling of clothes, which Papyrus interpreted as a 'no'.

“I STARED IT DOWN EVERY DAY DESPITE MY FEARS UNTIL I OVERCAME IT. GRADUAL EXPOSURE TO IT UNTIL I CONQUERED IT!” Papyrus held out his gloved hand under the clothes. “AND WITH MY HELP, YOU CAN DO THE SAME, SANS! I BELIEVE IN YOU!”

Two seconds elapsed before two tiny hand grasped his own, and his brother finally came out of the clearance rack with a watery grin.

“you will help me?” he asked shyly.

“OF COURSE, BROTHER! I’LL ALWAYS BE THERE TO PROTECT YOU!” Papyrus draped the galaxy jacket over Sans’s shoulders. It was a bit large on him, but his brother still looked great in it. “AN ENCOURAGEMENT GIFT!”

“thanks, papy, you’re the coolest!” 

Sans beamed at him, showing off his tooth gape. Papyrus practically glowed with happiness.

He, of course, paid for the jacket, and the two made their way back to the main mall area. Papyrus thought back to when his brother had been sick and not said anything; same with his nightmares and all those years his brother had suffered silently alone in the Underground. It was a quality that Sans always had, even as a babybones, it seemed.

“SANS, JUST KNOW THAT IF YOU EVER FEEL UNWELL OR SOMETHING CONCERNS YOU, YOU CAN ALWAYS SPEAK TO ME ABOUT IT. I AM A VERY GOOD LISTENER AND ADVICE GIVER, AFTER ALL!! NYEH HEH!” 

"i'll try."

Papyrus hoped for a more definitive answer, but it was still progress. He simply had to work harder to break his brother out of that habit.

**Notes for the Chapter:**

> First, I've never seen Watership Down (yes, that was the movie he saw), only the graphic clips and screenshots of it on youtube.
> 
> Second, yay! Sans finally got new clothes!


	4. Ticklish Bones Can Cause Magical Disappearances

Sans couldn’t seem to sit down as he watched the houses pass him through the window of Papyrus’s car. This would be the first time he would be away from his brother for a long period of time. Nearly a whole day. Papyrus had been called in to cover a shift at the mall, and he couldn’t say ‘NO’, even at the expense of having to leave his brother. But then Frisk recommended he drop Sans off at their place, where Asgore would be babysitting.

When Papyrus arrived in front of the enormous, two-story house, Sans unlocked his seatbelt and nearly jumped out of the car. He stared at the building with eye sockets the size of dinner plates, white eye lights shining brightly. 

“papy! house is big!” The babybones rattled with excitement, pointer finger pointing in the direction of Asgore’s home.

“YES, BROTHER, DUE TO HIS MAJESTY’S SIZE, HE HAD TO EXPAND THE HOUSE. IT IS QUITE MAGNIFICENT! WAIT UNTIL YOU SEE THE GARDEN!”

Papyrus swept his brother up onto his shoulders and dashed towards the front door. Sans laughed in elation. The door swung open before Papyrus even had to knock, both Frisk and the king of the monsters standing in the threshold.

“Howdy, Papyrus!” Asgore greeted, while Frisk waved at the two of them. His eyes fell upon the skeleton sitting on Papyrus’s shoulders. “And Sans! I am Asgore.”

Sans ducked and pressed himself against Papyrus’s head as he saw Asgore’s approaching paw. It was gigantic to Sans — as big as his skull!

“Don’t worry, Sans,” Frisk began. “Goat dad is super nice!”

Sans looked up and let the paw land on the top of his skull. As soon as the fur touched him, he leaned in and used his delicate arms to rub along Asgore’s hand.

“so soft!” He called out with a giggle, pupils dilating. 

Asgore carefully took the tiny skeleton into his arms, and Sans immediately latched onto it like a koala bear. His entire body just barely wrapped around one of Asgore’s arms. Papyrus beamed, relieved that his brother had taken a liking to their king.

“THANK YOU FOR VOLUNTEERING TO LOOK AFTER MY BROTHER, YOUR MAJESTY!”

“Not at all, Papyrus. And please, call me Asgore.”

“IF IT’S NOT A PROBLEM, THEN I WILL!” Papyrus exclaimed and glanced at his watch. “I MUST BE OFF! GOOD-BYE, SANS, I WILL SEE YOU IN A FEW HOURS!”

Papyrus gived a final wave to his brother, and then bounded towards his car. Asgore looked down at Sans, who was busy rubbing his cheeks against the white fur, chuckling every so often. Asgore cooed at the display, and the three of them went inside the house.

After a quick tour of the Dreemurr’s house, Asgore brought the two children into the living room and set Sans down on the couch. He made a disgruntled sound of protest, phalanges scrambling to grasp at Asgore’s fur.

“i wanna keep touching!” Sans cried.

“Don’t worry, little one, I’ll be right back.”

Asgore pet the top of Sans’s skull with a paw and stood up to grab some snacks from the kitchen. He, along with Frisk’s help, had baked a fresh batch of chocolate chip cookies. Asgore pulled out a plate and placed two large cookies on it. Then he poured steaming tea into two cups, added a splash of milk and a teaspoon of sugar. 

As he made his way back to the sitting room, he paused at the spin dryer in the laundry room. He was halfway into the room, about to sort out the freshly cleaned clothes, when he realized he still had a plate of cookies and tea on him. He could always sort the laundry later. Asgore stepped back into the spacious living room, and his soul froze at finding it completely devoid of children!

Asgore immediately thought the worst — that they’d run away. But then he heard shrill laughter coming from upstairs and reminded himself that Frisk had forgiven him; they’d accepted him as their adopted dad.

Feeling rather foolish, he made his way upstairs to find Sans jumping up and down on the double king-sized bed while Frisk bounced along on the undulating mattress, trying to stop the babybones. Giggles rang out from Sans every time he shot up into the air. At one point, after a particularly high jump, his trajectory went sideways, away from the bed and towards the back wall.

A distressed gasp fled out from Frisk’s mouth while Asgore scrambled to reach over to catch Sans. However, just as Sans was about to hit the wall, the young skeleton disappeared with a faint hum of spent magic. Asgore spun around the room, looking for Sans.

“Sans?” Frisk called out.

“surprise!” came a high-pitched voice from under the bed. 

Seconds later, a round, white skull popped out from the sheets hanging over the mattress.

“How did you do that?” Asgore gaped. 

“it’s a shortcut.”

Is that what he called it? Asgore wasn’t unfamiliar with Sans’s penchant for sneaky appearances and mysterious disappearances. He never had any idea how or where Sans learned the ability. Maybe now was a good time for him to learn more about his former Judge.

“What’s a shortcut?”

Frisk came over with a twinkle of interest in their eyes. Sans shrugged in response and simply answered, “magic.”

Then he peered around the room, seemingly bored with jumping on the bed. 

“Hey, Sans, do you wanna try some of the cookies I helped dad make?” Frisk asked, carefully grabbing one of Sans’s hands. They were so much smaller than their own, and Frisk fleetingly wondered how easily they could break.

“I left some in the living room,” Asgore said lamely, trying not to feel upset at getting ignored.

“Thanks, dad! You should join us as well!” 

Asgore perked up and suggested to carry them downstairs, but Frisk refused and led Sans back downstairs by their guiding hand. Asgore stayed behind to make sure everything was in order and there was nothing Sans could accidentally get hurt from. He would have to pay close attention to make sure Sans didn’t vanish randomly. Could his magic be starting to manifest? Or were the circumstances different due to the effects of the potion that had turned Sans this way?

Asgore made his way back downstairs, and as he neared the living room, he heard the two children’s conversation.

“is he really your dad?” Sans asked Frisk. “you’re not a monster.”

“He’s my adopted dad.”

“adopted... dad?”

“Yeah, just like how Toriel is my adopted mom.” Frisk took in a deep breath, and then continued quietly, “My real mom and dad weren’t very nice people.”

They fell silent. Asgore felt a pang in his soul and entered the living room, wanting to cheer Frisk up.

Sans clasped Frisk’s fleshy hands within his own and responded with a wide grin and shining eye lights, “i don’t know mom or dad too. it’s me and papy. he's cool and take good care of me. if you get sad, i be your bro too!”

Frisk wrapped their arms around the petite skeleton and hugged him tightly. “Ahhh, you are too cute, Sans! Thank you!”

Sans reciprocated back, though his arms only reached halfway around Frisk’s waste. Asgore smiled gently at the two children and scooped them up into his arm. 

“You and Papyrus are always welcomed here, Sans. And I will try to be the dad you never had, for all of you.”

Uncontrollable laughter burst forth from Sans’s teeth. Asgore stared at the laughing skeleton in his left arm, bemused. Frisk soon joined along.

“Haha, looks like Sans is ticklish!”

Frisk reached out their arms to Sans’s tiny chest and wiggled their fingers. Sans squirmed against the assault, only to make it worse as Asgore’s fur rubbed along his bare bones. Even Asgore joined in on the fun.

“hehhehehehe— haha… sto—!”

In a blink of an eye, Sans vanished from their sight! 

Asgore and Frisk scrambled around the house, in all the bedrooms, the bathrooms, under beds and even the closets, but could not find the babybones. Panic filled Asgore with every unsuccessful search of a room or a possible hiding spot. They had searched for nearly thirty minutes.

Where could Sans have disappeared to? Had he meant to or did his magic act up again? 

The possibility that Sans had left the house had Asgore sinking despondently into a chair. Even now, he was plagued with failures. What would Papyrus say or think? Or Toriel?

“Don’t worry, dad, I got an idea.” 

Frisk pulled out their phone and dialed Papyrus’s number. Within three rings, the taller skeleton’s boisterous voice rang through the communication device.

“HELLO, FRISK! IT IS THE GREAT PAPYRUS SPEAKING. HOW MAY I HELP YOU? IS MY BROTHER STAYING OUT OF TROUBLE?”

“Hey, Papyrus. Everything’s fine. I was just calling to ask what places Sans likes to hide?”

“OH? ARE YOU, PERHAPS, PLAYING HIDE AND SEEK? MY BROTHER WAS ALWAYS GREAT AT THAT GAME. BUT GIVEN THE MANY YEARS I HAVE LIVED WITH SANS, I HAVE PERFECTED THE ART OF FINDING THAT LAZYBONES!”

“Yeah, well, we need help finding him. You don’t have to tell us exactly. Just give us a hint.”

“OF COURSE! THOUGH HE NEVER ADMITS IT, HE LOVES WARM AND COMFY PLACES, ESPECIALLY IF HE TAKES A NAP AS HE HIDES!”

A lightbulb went off in Asgore’s head. Frisk glanced over at him, who nodded and immediately bounded out of the room, nearly shaking the whole house in his rush to the laundry room. He heard a continuous whistling sound that rose and faded in a steady rhythm. And sure enough, curled within the assortment of different clothes, almost hidden by them, was Sans snoring away.

Asgore sighed in relief and gently extracted Sans, along with the clothes, from the dryer. He carefully bundled Sans in the clothes to prevent his fur from rubbing against the skeleton’s bones, not wanting to wake him up from his slumber. Frisk had finished their conversation with Papyrus by the time Asgore arrived back in the kitchen. They smiled at him at the sight of the sleeping skeleton.

Asgore cradled Sans in his left arm and picked up a plate of cookies. It would be a perfect time to sit outside.

“Come, Frisk, will you join me in the garden to enjoy some tea and cookies?”

The human child nodded and grabbed the teapot along with three teacups — they had yet to finish the tea from earlier — and went outside. And as Asgore sat in his garden with Frisk while Sans slept in his arms, he felt peace for the first time that day.

**Notes for the Chapter:**

> I really wanted to write Asgore for the first time. Hopefully he didn't come off as too OOC.


	5. Some Humans Steal Children... Even Monster Children

**Summary for the Chapter:**

> Prompt by **wisepuma23** : if you're still open to prompts, i would like more protective!papyrus and he's a badass!!! like some human tries to sans away or something and papyrus is like super awesome, i mean like ON THE SAME LEVEL AS SANS' ADULT POWER kinda awesome  
> 

Excitement bubbled forth within Papyrus as he drove down the highway to the amusement park, with Sans in the back seat. He finally had a day off and decided to use that time wisely to spend some quality brother bonding time with Sans. From the front mirror, he could see the babybones staring in amazement at the rapidly changing scenery.

Before long, Papyrus had parked his car and paid for two tickets. They could hear the loud whooshing of the accelerating roller coasters, while joyous chatter resounded around them from the crowd of human and monster families. Sans’s bright eye lights were practically shaped like stars as he took in their surroundings. 

“papy! lookit that! it’s so fast and tall! i wanna go!”

Sans was pointing to a spiraling coaster with over an estimated 200-foot drop. 

“YOU’RE STILL TOO YOUNG, SANS. GIVE IT A FEW MORE YEARS, AND INCHES, THEN YOU MAY GO!”

Sans puffed out his cheeks and narrowed his eye sockets in a pout. It almost swayed him, but he resisted Sans’s methods of trying to guilt him into making a potentially horrible decision.

He was the Great Papyrus, and brother extraordinaire. He had to protect Sans from harm and unfairness. Even if he itched to go on the twisting roller coaster, if Sans could not go on it, then it would not be fair for him to ride it. 

Besides, where would he leave Sans? With the amount of people at the park, it would be so very easy to lose the diminutive babybones.

As the two of them strolled around the park, a middle-aged couple crashed into them. Literally. The lady wore a yellow sundress and had the widest smile Papyrus had ever seen. And the man wore a matching yellow shirt with tan trousers, also grinning broadly.

“My, what an absolutely adorable monster child,” the woman gushed, reaching out to caress Sans's cheekbones with one of her hands.

“Indeed, Martha,” the man agreed. He also reached out and placed a hand on Sans’s shoulders.

Although Papyrus mentally agreed that his brother was the cutest, he was rather put off by their touching Sans without even asking permission first. Sans seemed to have the same opinion, as the five-year-old monster pulled out of their intrusive touches and rushed behind Papyrus.

“THANK YOU FOR YOUR COMPLIMENTS. WE BETTER BE OFF! FAREWELL!”

He swept Sans up into his arms and power-walked away from the strange couple.

“they were weird, papy,” Sans commented.

“YES, THEY WERE. BUT NOT TO WORRY, SANS, I, THE GREAT PAPYRUS, SHALL KEEP YOU SAFE!”

They ended up going on the merry-go-round, where Sans almost fell off his horse if it wasn’t for Papyrus catching him with blue magic before he'd hit the rotating ground. Afterwards, they grabbed some food, a hot dog for Sans -- who doused it in five packets of ketchup -- and pizza for Papyrus. While on line, Papyrus caught a flash of yellow attire in his periphery; however, when he turned, he found nothing. Papyrus frowned.

The two continued to wander around the amusement park, Sans practically glowing after each kiddie ride. He especially loved the bumper cars, where the two of them shared one vehicle while they tried to avoid the other families’ cars. Sans would giggle mischievously and clap his tiny hands every time they miraculously dodge a car, or hit one out of nowhere. Papyrus wondered if he was discreetly using magic somehow.

But wasn’t Sans still too young to use magic? Unless that aspect of him hadn’t reverted to its child state? Papyrus decided he would ask Alphys about it next time he sees her.

It was about halfway through the day when disaster struck. 

Papyrus and Sans had been walking through all the carnival games. It was surprisingly crowded, with tons of children and parents. During the momentary period where Papyrus had his sights completely drawn to the game where players had to move a steel ring down a spiraling wire without touching it, he failed to notice Sans continuing to walk onward.

By the time he peered around for Sans, the skeleton child was nowhere to be seen.

Panic flooded his soul as he sprint to each game stall and searched around for his missing sibling. 

How could he be so inattentive as to not realize that Sans had wandered off?

Papyrus was so disappointed in himself, though he didn’t let it stop him from running around to look for the babybones. He had never ran so fast in his entire life, not even when he trained with Undyne to become a Royal Guard. At one point, he reported his missing skeleton brother to the security in the park, and then continued on his search.

Finally when he was nearly out of his wits with worry, he took a couple of unnecessary breaths to calm himself enough to come up with a plan. He decided his best bet was to track down his brother’s magical signature.

Each monster had a distinctive stamp to their magic, much like humans and their fingerprints. It normally takes a large amount of time, practice and talent to recognize another monster’s signature, but since Papyrus grew up with Sans -- and only Sans -- since _he_ was a babybones, he could pick it out in a crowd if he concentrated.

And sure enough, within five minutes, Papyrus detected a faint trace of Sans’s magic in the parking lot of the amusement park. 

Papyrus sped off into the direction as fast as he could, ignoring all the strange stares he received from humans watching a lanky skeleton run. As he drew closer, he heard shouting. 

“Oh, hush, little one! We’ll take good care of you!” a familiar female voice reassured.

He came across the scene of the earlier human couple wrestling to keep a squirming Sans from escaping the woman's arms, which he was wrapped within. He bit the lady’s hand, who let out a high-pitched screech. The man responded by smacking Sans across the cheek with his hand; he used so much force that it jerked the skeleton’s skull to the side. 

Something snapped within Papyrus as the slap replayed in his mind several times. His eye sockets flashed orange and blue. Five giant, draconic skulls materialized around the two humans and roared. 

“IF YOU ATTACK MY BROTHER AGAIN, I WILL GIVE YOU AN UNPLEASANT TIME!”

Horror transfixed their faces, and the woman released Sans. Before Papyrus had the chance to use blue magic to grab him, Sans vanished and appeared in Papyrus’s arms. Papyrus blinked twice in shock. 

“papy!”

Despite the forming faint bruise the size of a human hand on his brother’s face, Sans beamed up at him with open admiration.

“ARE YOU HURT ANYWHERE ELSE, SANS? I AM SO SORRY THIS HAPPENED. I HAVE FAILED YOU AS A BROTHER!”

Sans shook his head furiously and wrapped his arms around Papyrus.

“you safed me, papy! you’re superhero!”

Tears of happiness and relief gushed out of Papyrus’s eye socket, and he returned the hug tightly. 

He heard the two humans take a step, and turned to them. They had their backs to them, in a sprinting position. But before they took a single step, a cage of bones surrounded them, trapping them inside. 

With Sans still held protectively against his chest, Papyrus marched in front of the trapped couple and declared, “I WILL REPORT YOU TO THE PARK SECURITY FOR YOUR CRIME! AND YOU ARE NOT TO MOVE UNTIL THEY ARRIVE, UNDERSTOOD?” His voice dipped into a low growl. “THE BLASTERS WILL KEEP YOU COMPANY!”

Three of them dissipated, leaving two to guard them. Sans had his sockets wide open, gawking at the floating skulls. Even as Papyrus went to the security office, the smaller skeleton had his eye lights trained on the blasters.


End file.
